Compute local variable liveness before translation to SSA.

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index a0e412e6d4623f37371bea949c72aff9b4ab7885..68d2bffd0718fcad87d1556858400b1547cc8bd4 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -212,9 +212,17 @@ static bool CompileParsedFunctionHelper(const ParsedFunction& parsed_function,
       optimizer.Canonicalize();
       DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
+      if (FLAG_print_flow_graph || FLAG_print_flow_graph_optimized) {
+        FlowGraphPrinter::PrintGraph("Before BranchSimplifier", flow_graph);
+      }
+
       BranchSimplifier::Simplify(flow_graph);
       DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
+      if (FLAG_print_flow_graph || FLAG_print_flow_graph_optimized) {
+        FlowGraphPrinter::PrintGraph("Before CP", flow_graph);
+      }
+
       if (FLAG_constant_propagation) {
         ConstantPropagator::Optimize(flow_graph);
         DEBUG_ASSERT(flow_graph->VerifyUseLists());
@@ -275,6 +283,10 @@ static bool CompileParsedFunctionHelper(const ParsedFunction& parsed_function,
       optimizer.Canonicalize();
       DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
+      if (FLAG_print_flow_graph || FLAG_print_flow_graph_optimized) {
+        FlowGraphPrinter::PrintGraph("Before register allocation", flow_graph);
+      }
+
       // Perform register allocation on the SSA graph.
       FlowGraphAllocator allocator(*flow_graph);
       allocator.AllocateRegisters();